What are the factors in determining the diameter of the bit for cutout being used on a CNC? I currently use a 1/2" two flute compression, which seems to work fine with my machine. I read a lot about others using 3/8" compression. Why? Is it horsepower? Is it speed of feed? Is it hold down? Is it cost? Is it a waste issue? Is it just what you were told to run from the machine manufacturer? Hoping some more seasoned CNC users can answer these.
From contributor M:
I think you will find this really boils down to two major considerations. The first is rigidity. A 1/2" bit is inherently more rigid than a 3/8" bit. Primarily because of the additional mass of the diameter. Normally larger diameter bits provide for a longer cutting edge. So typically most people would pay a little extra for a little more bit. Then came NBM (nested base manufacturing), where whole sheets are optimized and cut out on a router. Then the smaller diameter 3/8" bit began to gain in popularity, primarily because the swath left from a 3/8" bit is 25% less than that of a 1/2" bit. Less swath in the nested base world equals less vacuum loss (providing for cleaner cuts and safer operation) and to some degree more potential yield out of one sheet of goods.
Contributor C, don't throw the solid carbide tools away. Courmatt has a recycling program available. The cost of raw material has gone up considerably in the last year (the Chinese use supply and demand system). Anything we can do to reduce mining of this product helps us all. The info is on our (Courmatt's) web site, and we also pay for the freight.